Stock-based Compensation Plans - Additional Information 4 (Detail) - USD ($) $ in Thousands, shares in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Maximum percentage of employees contribution									75.00%
Maximum percentage of employers contribution in cash									6.00%
Employer contribution									$ 5,400	$ 5,800	$ 5,100
Deferred compensation plan vesting period									3 years
Deferred compensation plan	$ (960)	$ 8,871	$ 11,142	$ (3,581)	$ 18,072	$ (223)	$ (6,615)	$ 7,397	$ 15,472	$ 18,631	$ 50,915
Shares held in rabbi trust total	3.2				2.6				3.2	2.6
Vested shares held in rabbi trust	2.7				2.4				2.7	2.4